Ceiling mounted indoor units mounted on the ceiling of a room have been used as indoor units for air conditioning devices. An indoor unit of this type includes an indoor unit body including an indoor heat exchanger and a blower fan that are housed in a casing having an opened bottom, and a decorative panel attached to the bottom of the indoor unit body. The decorative panel has a suction port in a center portion thereof, in which a suction grill is fitted.
The suction grill of the indoor unit described above is comprised of a square outer frame member and a large number of bars arranged parallel to each other between two opposing sides of the outer frame member. In this configuration, the suction grill is provided with a plurality of rectangular suction holes arranged parallel to each other, each of which has longer sides that are substantially as long as one of the sides of the outer frame member.